figure out way to sync `isDelegationEligble` w the upstream logic

[bap2pecs]

@bap2pecs cloned issue babylonchain/babylon-finality-gadget#19 on 2024-06-21:

we implemented exact logic as in https://github.com/babylonchain/babylon-private/blob/c5a8d317091e2965e20ea56fa10e98d34aaa3547/x/btcstaking/types/btc_delegation.go#L111-L119

but the upstream logic could change

this is to figure out a way to make sure the two codebase are in sycn

but probably a low-pri